Millions of passengers move through domestic airports every day. Travellers routinely pack everything from antlers and artificial skeleton bones to tortilla presses without incident. Bring any form of cannabis on board, however, and you enter a completely different reality.
Air travel falls under federal rules, and that causes real headaches for people flying out of states where weed is legal. If you travel into a place where recreational use is banned, you are putting yourself at serious legal risk.